This invention relates to magnetic tape transport, and particularly to tape guides therefor.
Various synthetic or so-called "plastic" materials have found uses in the economical manufacture of magnetic tape transport and of components therefor, such as the magnetic tape cassette described in U.S. Pat. No. 3,756,329, which is meant for use in an automatically-threading transport mechanism such as the carrousel apparatus disclosed in U.S. Pat. No. 3,720,794.
In the machine of this patent, the tape loop that extends between the two reels of the cassette is pulled into the transport machine, and into contact with the magnetic heads, by means of a vacuum apparatus.
One problem that has developed in the use of plastic materials for such cassettes, is that the surfaces thereof, over which the tape passes in a tensioned, rubbing fashion, and particularly surfaces such as those of guide posts, tend to collect static charges of electricity, so that the tape clings to the guide posts when the tape is at rest. The cassette of U.S. Pat. No. 3,756,329, for example, has a pair of guide posts for holding the tape that extends between the reels of the cassette in a favorable position to be acted upon by the vacuum pressure differential of the transport, for threading. However, the build-up of static electrical charges between the tape and guide posts, and the resulting clinging of the tape to the posts, inhibits and interferes with the desired vacuum-threading operation and, on occasion, causes complete malfunction of the apparatus.
Accordingly, it is an object of the present invention to provide anti-static protection for magnetic tape and the guide means therefor.
It is a further object of the present invention to provide an improved cassette for the threading of magnetic tape into a tape transport.